Method for optoelectronically inspecting pharmaceutical articles

ABSTRACT

In a method for optoelectronically inspecting pharmaceutical capsules ( 2 ) in a capsule filling machine ( 1 ), the pharmaceutical capsules ( 2 ) are fed in single file from a station ( 3 ) where the capsules ( 2 ) are made to a capsule ( 2 ) outfeed portion ( 8 ) of the machine ( 1 ) along a defined feed path (P) passing through an inspection station ( 13 ). In the inspection station ( 13 ), each pharmaceutical capsule ( 2 ) passes through an electromagnetic field created by coherent, polarised light radiation.

TECHNICAL FIELD

The present invention relates to a method for optoelectronicallyinspecting pharmaceutical articles.

In particular, the present invention can be advantageously applied tocapsule filling machines for making hard gelatin capsules of the typewith lid and body, filled with doses of pharmaceutical material inpowder or particulate form, which the present specification expresslyrefers to but without restricting the scope of the invention, in orderto check defined properties of the capsules through an optoelectronicinspection.

DISCLOSURE OF THE INVENTION

The invention provides a method for optoelectronically inspectingpharmaceutical articles in a machine that makes the articles,characterised in that the pharmaceutical articles are fed in single filefrom a station where the articles are made to an outfeed station of thearticles themselves along a defined feed path passing through aninspection station; each pharmaceutical article passing through anelectromagnetic field. Treated by coherent, polarised light radiation inthe inspection station.

Preferably, the electromagnetic field is produced by a laser beam sourceand the articles comprise hard gelatin capsules of the type with lid andbody containing doses of pharmaceutical material in powder orparticulate form, the machine that makes the articles comprising acapsule filling machine that makes the pharmaceutical capsules; thecrossing of the electromagnetic field permitting detection of the levelto which the capsules are filled with the pharmaceutical material.

DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanyingdrawings which illustrate a preferred, non-restricting embodiment of aunit, implementing the method according to the invention, foroptoelectronically inspecting pharmaceutical articles, and in which:

FIG. 1 is a schematic plan view, partly in cross section and with someparts cut away for clarity, of a machine equipped with an operating unitimplementing the method according to the invention;

FIG. 2 is a schematic front view, and a cross section through lineII-II, of a detail of the unit of FIG. 1; and

FIG. 3 is a side view in cross section of the same detail as that shownin FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

With reference to FIGS. 1 and 2, the numeral 1 denotes in its entirety amachine for filling hard gelatin capsules of known type, each having alid C and a body F, with doses of pharmaceutical material M, inparticular pharmaceutical material M in powder or particulate form, suchas, for example, microtablets or pellets. The capsule filling machine 1is of well known type and basically comprises a station 3 for making thecapsules 2, the station 3 in turn comprising a drum 4 that rotates,preferably with continuous motion, in the direction indicated by thearrow K in FIG. 1, and being equipped on its periphery with a set ofseats or bushes 5 for accommodating the capsules 2 once closed andfilled with the material M.

The material M is fed to the drum 4 in a known manner, which is notillustrated, through a central hopper 10 containing the material M whichis dosed into the capsules 2 through a dosing system SD of the type,disclosed for example, in Italian Patent IT 1304779, with pistons thatmove inside respective cylindrical dosing chambers.

In the bushes 5 of the drum 4, each capsule 2 is set in a verticalposition, that is to say, with its longitudinal axis X positionedvertically and with the lid C at the top and the body F below.

From the drum 4, each capsule 2 is ejected in succession from arespective bush 5, by customary expulsion means, which are notillustrated, and, at the station 3, is transferred to a radial seat 6 ona starwheel conveyor 7 that rotates in synchrony with the drum 4 in thedirection Z of FIG. 1 opposite the direction of rotation K of the drum4.

As illustrated in FIG. 1, the conveyor 7 is designed to feed thecapsules 2 in succession from a station 3 to an outfeed portion 8 of themachine 1 along a semicircular feed path P, each capsule 2 being held inthe vertical position in the respective seat 6 by suction created insidea suction chamber 9 connected to a vacuum source S and to each seat 6through a respective conduit 11. The outfeed portion 8 comprises acapsule 2 conveyor channel 12 and a nozzle 12 a connected to a source ofair under pressure (not illustrated) to expel the capsules 2 from theconveyor channel 12, the latter being connected in a known manner whichis not illustrated, into an infeed hopper of a packaging machine, forexample a blister packer or a machine for filling phials with thecapsules 2.

FIG. 1 also shows that between the station 3 and the outfeed portion 8,the path P passes through a station 13 for inspecting the capsules 2.

As illustrated in FIGS. 1 and 2, the inspection station 13 comprises acovering structure 14 defined by an anodised obscure chamber enclosing aunit 15 for supporting the source 16 of a laser beam, that is to say, abeam of high-frequency monochromatic coherent polarised light, which isdiffused inside the structure 14 on each capsule 2 held in a respectiveseat 6, the light then being intercepted by an optical sensor 17 ofknown CCD matrix type mounted on the side of the unit 15 opposite thelaser source 16.

From an operational point of view, optimum results are obtained usinglaser beam sources of the He Ne type at 623 nanometres with focal spot0.8 millimetres in diameter, or of the diode type at 650 nanometres withfocal spot 2 millimetres in diameter.

More specifically, as each capsule 2 passes through the inspectionstation 13 supported by the seat 6 of the starwheel conveyor 7, with itsaxis X perfectly vertical, it enters the structure 14 and crosses theelectromagnetic field E created by the laser beam, which checks that itcontains a dose of material M and that the material M fills it to thecorrect level.

As shown in FIG. 3, the unit 15 is mounted on a shaft 18 which isrotationally driven by a customary motor (not illustrated) about ahorizontal axis Y, and, during use, is designed to be turned through adefined angle α relative to the axis X so that the level of the materialM inside the capsule 2 can be optoelectronically checked from differentangles.

Preferably, the angle α is varied from 0 to 30°.

The station 13 also comprises a monitoring device 19 that is connectedto the sensor 17 and that is designed to receive from the sensor 17 asignal relating to the measured level of material M with which eachcapsule 2 is filled, to compare this measured value with a presetreference value, and to generate an output signal that activates adevice 20 for rejecting any capsules 2 that do not conform with thereference value.

As illustrated in FIG. 1, the rejection device 20 comprises a firstnozzle 21, which is connected in a known manner that is not illustratedto a source of air under pressure and which, on receiving a controlsignal from the monitoring device 19, issues a jet of air which, byovercoming the suction in the seats 6, diverts from the path Pindividual non-conforming capsules 2, causing them to be expelled andfed out through a conveyor channel 23 leading into a rejection container22.

The monitoring device 19 is also connected to the machine 1 system SDwhich doses the pharmaceutical material M so that, if a significantaverage percentage of the checked capsules 2 are found to beunsatisfactory, the device 19 sends a feedback signal to the dosingsystem SD in order to automatically adjust the material M dosingparameters of the machine 1.

Again with reference to FIG. 1, the rejection device 20 also comprises asecond nozzle 24, which is connected in a known manner that is notillustrated to the source of air under pressure and which, on receivinga control signal from the monitoring device 19, issues a jet of airwhich diverts from the path P a specified number of sample capsules 2,causing them to be expelled and fed out through a conveyor channel 26leading into a rejection container 25.

Advantageously, the sample capsules 2 collected in the container 25 canbe weighed on analytical precision balances and the weights thusmeasured, from which the material M filling levels can be calculated,are transferred to the memory medium of a personal computer and comparedwith the filling levels measured by the monitoring device 19 to checkfor significant deviations between the two sets of values.

Thus, the unit 14 can be periodically tested for working efficiency andwhen deviations are found in a significant average number of samples,the system SD for dosing the material M in the capsule filling machine 1can be adjusted accordingly.

To conclude, it is evident that the method can be used to optimally andautomatically inspect, by electronic means within the machine 1, all thecapsules 2 made by the machine 1 itself to check that they have beenfilled to the right level. Furthermore, the filling level of only aspecified quantity of sample capsules 2 can also be checked.

1. A method for optoelectronically inspecting pharmaceutical articles(2) in a machine (1) that makes the articles (2), characterised in thatthe pharmaceutical articles (2) are fed in single file from a station(3) where the articles (2) are made to an outfeed portion (8) of themachine (1) along a defined feed path (P) passing through an inspectionstation (13); each pharmaceutical article (2), as it travels through theinspection station (13), passing through an electromagnetic field (E)created by coherent polarised light.
 2. The method according to claim 1,characterised in that the electromagnetic field (E) is created by alaser beam source (16).
 3. The method according to claim 1,characterised in that the articles (2) comprise hard gelatin capsules(2) of the type with lid and body (CF) containing doses ofpharmaceutical material (M) in powder or particulate form, and in thatthe machine (1) comprises a capsule filling machine (1) that makes thepharmaceutical capsules (2); the crossing of the electromagnetic field(E) permitting detection that the capsules (2) have been filled withdoses of material (M).
 4. The method according to one of claims 2 or 3,characterised in that the electromagnetic field (E) is created inside astructure (14) which is located in the inspection station (13) and whichencloses a unit (15) for supporting the laser beam source (16) and, onthe opposite side, optical sensor means (17) designed to intercept thelaser beam; each capsule (2) crossing electromagnetic field (E) betweenthe laser beam, source (16) and the optical sensor means (17) being heldby suction in a seat (6) of a rotary conveyor (7) with suction seats(6).
 5. The method according to claim 4, characterised in that thesupporting unit (15) is mounted on a shaft (18) that rotates about ahorizontal axis (Y) and in that each capsule (2) is held on therespective seat (6) with its longitudinal axis (X) positionedvertically; the method comprising the step of turning the unit (15)through a defined angle (a) relative to the longitudinal vertical axis(X) of the capsule (2).
 6. The method according to claim 5,characterised in that the unit (15) is turned through an angle (a)ranging from 0° to 30°.
 7. The method according to claim 4,characterised in that it comprises a monitoring device (19) connected tothe optical sensor means ( 17); the method comprising the step of themonitoring device (19) receiving a measured value from the opticalsensor means (17), comparing this measured value with a peset referencevalue, and sending an output signal that activates a device (20) forrejecting the articles (2) that do not conform with the reference value.8. The method according to claim 7, characterised in that the rejectiondevice (20) is located upstream of the outfeed portion (8) on the path(P); the non-conforming capsules (2) being diverted from the path (P) bypneumatic deflecting means (21), causing them to be expelled into arejection container (22).
 9. The method according to claim 7,characterised in that the monitoring device (19) is connected to a unit(10, SD) for feeding and dosing the pharmaceutical material (M) in thecapsule filling machine (1); the method comprising the step of themonitoring device (19) sending a feedback adjustment signal to the feedand dosing unit (10,SD).